Enrich massBreakdown elements with uID-link to the corresponding component

Some elements in CPACS can be defined via sequences both where we define geometric elements and in the massBreakdown. For example the wings:

<wings>
    <wing uID="myFavoriteWing">...</wing>
    <wing uID="anotherWing">...</wing>
    <wing uID="aLittleWing">...</wing>
</wings>

and

<mWingsStructure>
    <massDescription>...</massDescription>
    <mWingStructure>
         <massDescription>
             <!-- Description: UID of the component which serves as parent element, i.e. whose coordinate system is to be used as a reference for the mass properties (CoG location, orientation and massInertia). Thus, two cases can occur: (1) it is set: local coordinate system of the parent; (2) it is not set: global CPACS coordinate system. " -->
             <parentUID>...</parentUID>
             <!-- PROPOSAL: -->
             <!-- Description: UID of the component which contains more detailed information, e.g. on geometric dimensions. It does not influence the coordinate systems definition. -->
             <componentUID>myFavoriteWing</componentUID>
         </massDescription>
    </mWingStructure>
</mWingsStructure>

The knowledge which mass belongs to which wing definition is implicit and current practice is to rely on the sequence of the elements (bad idea!). Should we add something like an optional componentUID which just directs to the components containing more detailed information, but not influencing the optional parentUID-defnition (see #733).

Remark: As this would be part of genericMassType it would be possible to use the element within each massDescription node. So in some cases it would not be useful (e.g., in mWing**s**Structure/massDescription). But maybe this is not a real issue?

What do you think?

DLR-SL / CPACS

Enrich massBreakdown elements with uID-link to the corresponding component #765